The disclosure relates to formed films, more specifically three-dimensional formed films for use as transfer layers in absorbent articles.
Absorbent articles are articles that are generally used once or a limited number of times for the temporary collection of bodily fluids. Such articles include diapers, adult incontinent products, feminine hygiene products, bandages and similar articles. In general, these articles have a topsheet, which is positioned adjacent the skin of the user, a backsheet, which is opposite the topsheet and may, in use, be positioned adjacent to the clothes of the wearer, and an absorbent core positioned between the topsheet and the backsheet. In most instances, the topsheet is pervious to the bodily fluids and the backsheet is impervious to such fluids, thus protecting the clothing of the wearer from leaks. The absorbent core is designed to collect and hold the bodily fluids until the article can be disposed of and changed with a fresh article.
Transfer layers, which are also known in the art as acquisition distribution layers or “ADL”, have been used in absorbent articles. Both nonwoven webs and three-dimensional formed films have found use as transfer layer in the past. A transfer layer is typically positioned between the topsheet and the absorbent core and generally improves the efficiency of the article to absorb and retain fluids. For example, transfer layers have been used to provide void volume, which serves as a temporary reservoir to collect and hold fluids until the fluids can be absorbed by the core. In addition, transfer layers have been employed to promote lateral flow of fluids in a direction generally parallel to the plane of the transfer layer, thereby permitting more of the core to be used to absorb fluids. See, for example, U.S. Pat. No. 4,324,247.
Transfer layers may also function to prevent or reduce rewet, which is a phenomenon in which fluids are released from the core and find their way back to the surface of the topsheet, thus “re-wetting” the topsheet. Rewet creates an unpleasant damp feeling to the user of the article and is therefore is important to minimize or eliminate. Finally, transfer layers have been known to be used to reduce surface wetness on the topsheet by facilitating transfer of static fluids that would otherwise tend to remain on the topsheet surface and again create a damp, unpleasant feeling.
There is a continuing need for transfer layers that more effectively promote distribution of fluids over the absorbent core, provide more comfort for the wearer, reduce surface wetness in the topsheet, and prevent or reduce rewet. There is also a need for transfer layers with less loft to reduce the overall thickness of absorbent article without loss of functionality.